Process for the production of fluorescent or phosphorescent substances



Patented Oct. 10, 1933 UNITED STA PROCESS FOR THE PRODUCTION OF FLU- ORESCENT OB PHOSPHORESCENT SUB- STANCES Emil Rupp, Glienicke, Germany, assignor to General Electric Company, a corporationof New York No Drawing. Application :February Seriaal No. 590,321, and in Germany February 4 Claims.

terial in the order of 0.1 to 1%, parts by weight,

by the method of fusing or sintering, using a suitable flux material in this latter method.

The object of. the present invention is to produce a fluorescent or phosphorescent material consisting of the commonly known principal materials and heavy metals by an electrical transierence of the metal constituent to the principal material. Still further objects and advantages, attaching to the device and to its use 0 and operation will be apparent to those skilled in the art from the following particular description.

In accordance with this object the invention consists in the new and novel features of operation and the new and original arrangements and combinations of steps in the process hereinafter described and-more particularly set forth in the claims.

The principal material, such as one of those disclosed above, is arranged between the electrodes, said electrodes consist of that same metallic material whichis to be incorporated in the principal material. The principal material,

having poor electrical conducting characteristics, is brought to a high temperature when an 5 between may be conveniently described as a kind of electrolytic effect and will be referred to ,hereinafter as electrolysis. director alternatin'g current can be used as In order that the fluorescent or phosphorescent material produced have maximum activity the quantity of deposited metallic material must reach a certain optimum for certain materials, this depends on the nature of the particular principal material and the particular metallic material used.

The yield in this process, as in all electrolysis, is

proportional to the product of the current strength and the time.

The following examples are given by way of illustrating practical applications of the present invention:

Example 1.The' materials used are sodium chloride NaCl) and manganese. A crystal of rock salt is placed between two manganese electrodes. The apparatus is then heated in a furnace to a temperature of 450 C. to increase the electrical conductivity of said sodium chloride while a current of sufiicient voltage to cause 5-10 milli-amperes to flow through the rock salt crystal is applied to said electrodes. This is continued for approximately 30 minutes. The crystal is then cooled and upon being irradiated glows with an intense yellow color.

Example 2.-The materials used are zinc sulphide and copper. Commercial zinc sulphide powder is pressed between copper electrodes and electrolyzed at 600 C for about half an hour by a current of 10 to 20 milli-amperes. When cooled and irradiated the powder sends out a green glow.

A plurality of different metallic materials may be introduced into a single body of principal material by this process by substituting for one set of electrodes of a certain metallic material another set of electrodes of a different metallic material during the carrying out of the process, and further, particularly where alternating current is used, electrodes of difierent metallic material may be used for the same purpose.

Although I have shown and described and have pointed out in the annexedclaims certain novel features of the invention, it will be understood that various omissions, substitutions 1 and changes in the several steps of the process and its operation may be made by those skilled in the art without departing from the broad spirit and scope of the invention.

What I claim as new and desirev to secure by Letters Patent oi the United States is:---

1. A process for the production of phosphorvterial and a metallic addition which comprises the steps of interposing a body of the principal material, which is a poor electrical conductor, between two electrodes consisting of that metal desired to be incorporated in said principal material, heating said electrodes and. said body of principal material to increase the electrical conductivity of. said principal material and applying a suitable electric current to said electrodes for a suflicient period to transfer a desired escent material consisting of a principal maquantity of the metallic material from said electrodes to said principal material.

2. A process for the production of phosphor escent material consisting of sodium chloride and an addition of manganese which comprises the steps of interposing a body of sodium chloride, which is a poor electrical conductor, between two electrodes consisting of that metal desired to be incorporated in said principal material, heating said electrodes and said body to a temperature of approximately 450 C. to increase the electrical conductivity of said body of sodium chloride and applying an electrical current of approximately 5-10 milli-amperes to said electrodes for approximately 30 minutes to effect a transposition of manganese particles from said electrodes to the body of sodium chloride interposed between said electrodes.

3. A process for the production of phosphorescent material consisting of zinc sulphide and an addition of copper which comprises the steps of interposing a body of zinc sulphide, which is a poor electrical conductor, between two copper electrodes, heating said electrodes and said body to a temperature of approximately 600 C. to increase the electrical conductivity of said body of zinc sulphide and applying an electrical current of approximately 10-20 milli-amperes to said electrodes for approximately 30 minutes to effect a transposition of copper particles from said electrodes to the body of zinc sulphide interposed between said electrodes.

4. A phosphoresent, fluorescent body comprising sodium chloride having incorporated therein an electrically deposited addition of manganese.

EMIL RUPP. 

